<?php
class Inchoo_Cpa_Helper_Data extends Mage_Core_Helper_Abstract
{
	public function resizeImage($imageName, $width=NULL, $height=NULL, $imagePath=NULL)
	{
		$imagePath = str_replace("/", DS, $imagePath);
		$imagePathFull = Mage::getBaseDir('media') . DS . $imagePath . DS . $imageName;
	 
		if($width == NULL && $height == NULL) {
			$width = 100;
			$height = 100;
		}
		$resizePath = $width . 'x' . $height;
		$resizePathFull = Mage::getBaseDir('media') . DS . $imagePath . DS . $resizePath . DS . $imageName;
	 
		if (file_exists($imagePathFull) && !file_exists($resizePathFull)) {
			$imageObj = new Varien_Image($imagePathFull);
			$imageObj->constrainOnly(TRUE);
			$imageObj->keepAspectRatio(TRUE);
			$imageObj->resize($width,$height);
			$imageObj->save($resizePathFull);
		}
	 
		$imagePath=str_replace(DS, "/", $imagePath);
		return Mage::getBaseUrl("media") . $imagePath . "/" . $resizePath . "/" . $imageName;
	}
}